[PATCH AUTOSEL 6.13 10/21] platform/x86/intel: pmc: fix ltr decode in pmc_core_ltr_show()

Sasha Levin
2025-02-11T01:30:10Z

From: Dmitry Kandybka <d.kandybka@gmail.com>

[ Upstream commit 583ef25bb2a094813351a727ddec38b35a15b9f8 ]

In pmc_core_ltr_show(), promote 'val' to 'u64' to avoid possible integer
overflow. Values (10 bit) are multiplied by the scale, the result of
expression is in a range from 1 to 34,326,183,936 which is bigger then
UINT32_MAX. Compile tested only.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Dmitry Kandybka <d.kandybka@gmail.com>
Reviewed-by: Rajneesh Bhardwaj <irenic.rajneesh@gmail.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20250123220739.68087-1-d.kandybka@gmail.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/platform/x86/intel/pmc/core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index 3e7f99ac8c941..c5dae640a0b2b 100644
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -625,8 +625,8 @@ static u32 convert_ltr_scale(u32 val)
static int pmc_core_ltr_show(struct seq_file *s, void *unused)
{
struct pmc_dev *pmcdev = s->private;
- u64 decoded_snoop_ltr, decoded_non_snoop_ltr;
- u32 ltr_raw_data, scale, val;
+ u64 decoded_snoop_ltr, decoded_non_snoop_ltr, val;
+ u32 ltr_raw_data, scale;
u16 snoop_ltr, nonsnoop_ltr;
unsigned int i, index, ltr_index = 0;

--
2.39.5